Gearbox Trouble Disco 2 - pls help

[nickcalc]

I need help urgently with this one please: my 1999 V8 Disco 2 appears to have gearbox trouble: in the last few weeks I have noticed that the car was having trouble downshifting, particularly when travelling up a gradient. The problem became really serious yesterday arvo driving on the highway as the car seemed to have lost its ability to "kikdown": when putting my foot down, the motor revs up with no down gear shift...particularly when overtaking or going uphill, it's like travelling in top gear and the car eventually runs out of steam. I am no mechanic but this appears to be due to the gearbox. Has anyone encountered this problem before, is it likely to be due to an electronic fault? Many thanks in advance any help is appreciated as I am travelling and I think this one has potential to get me stranded! Advice from experienced guys will certainly help before I will have to get to a workshop or manage to limp back home.

Cheers,

Nick C.

[davros]

Does the "sport" button have any influence on this? What if you manually change the gears on the selector? It may get you home perhaps - but not if it's mechanical.

Only issues I've heard of are failure of the sprag clutch to engage (that's when the units "locks up" when cruising); maybe it can also "lock up" and fail to dis-engage?
The slip test in RAVE is another one to check, but it just checks if the unit is slipping. Put it in drive, left foot brake and plant it, from memory the tacho should be around 3000 rpm but not reving out. Don't do this more than once in a hour or so - you don't want to burn anything out! And no longer that 5 seconds or so, just to get a reading.

I'm no expert, look fwd to reading anyones answers to your problem

Dave

PS I am not sure if fluid level or dirty fluid would play a part in this, but it's worth checking - with the fluid warm (i think it says 40deg C on the auto sump - and the engine running in "P", vehicle on the level, the fluid should be just dribbling out of the plug, not gushing and not invisible! Also, old, dirty fluid may cause some issues.

To really clean out the old fluid, you can get it flushed at a dealer or I can give you some more info - wait and see what otheres reckon about the issue first though.

[nickcalc]

Does the "sport" button have any influence on this? What if you manually change the gears on the selector? It may get you home perhaps - but not if it's mechanical.

Only issues I've heard of are failure of the sprag clutch to engage (that's when the units "locks up" when cruising); maybe it can also "lock up" and fail to dis-engage?
The slip test in RAVE is another one to check, but it just checks if the unit is slipping. Put it in drive, left foot brake and plant it, from memory the tacho should be around 3000 rpm but not reving out. Don't do this more than once in a hour or so - you don't want to burn anything out! And no longer that 5 seconds or so, just to get a reading.

I'm no expert, look fwd to reading anyones answers to your problem

Dave

PS I am not sure if fluid level or dirty fluid would play a part in this, but it's worth checking - with the fluid warm (i think it says 40deg C on the auto sump - and the engine running in "P", vehicle on the level, the fluid should be just dribbling out of the plug, not gushing and not invisible! Also, old, dirty fluid may cause some issues.

To really clean out the old fluid, you can get it flushed at a dealer or I can give you some more info - wait and see what otheres reckon about the issue first though.
Dave, thank you very much for your reply! I have attempted using the car in Sport mode and manually shifting the gears...the car behaved just the same and that's another reason why I tend to believe that it may be an elecronic fault rather than a mechanical one...I am gonna perform the test you suggested and let you know! I really appreciate your help mate, cheers

Nick C.

[davros]

Another possible check is in low range - does the "manual mode" work? ie when you use the "sport" button in low range it should say "m" on the dash and allow you to change gears at will. Be a slow trip though :) !
I would still suspect either electronic or mechanical... if it's stuck in a gear, it's not going to matter what the computer tells it to do!
A diagnostic computer may allow you to find out more, like a nannocom, if anyone's in ur area?

Does the car rev normally in park or neutral?

Dave

[nickcalc]

Hi again Dave! Thanks again for the help, well you see the car does not seem to be stuck in any one gear ie, it upshifts well up to cruising speed on a flat road...the problems start when attempting a climb or attemtping to overtake when you need a lower gear. There seems to be no limits on its' ability to rev freely when in neutral.

Nick

[davros]

Cheers mate,

Well it sound like what - at least on older cars - is called the "kickdown" when you stomp it. Anyone know how to adjust this on a D2???

Dave

[George130]

It does sound like the kick down. Is it still a cable on the D2?
If so then it will be attached to the accellerator peddle and will have to moundting positions.

If what you are experiencing is the engine revs increasing while driving while loosing speed they you could have done the lock up clutch.

When was it last serviced as glogged filter and dirty oil won't help. This should show up as harsh gear changes and is also caused by low oil levels.

[davros]

Checked RAVE - there is no kickdown cable it's a computer calculated thing... Nannocom time I would say...

[justinc]

The MAF(Mass airflow meter) plays a very important part in trans shifting and engine power output in D2 V8 and Td5's. Worse effect in V8 model when knackered. It is a common problem and is easily proved by fitting a known working example and test driving.
They will usually show no fault codes, just feeding wrong info to ecu's.
D2 V8 and Td5 both have electronically controlled trans, no cables.
JC

[ashtrans]

The MAF(Mass airflow meter) plays a very important part in trans shifting and engine power output in D2 V8 and Td5's. Worse effect in V8 model when knackered. It is a common problem and is easily proved by fitting a known working example and test driving.
They will usually show no fault codes, just feeding wrong info to ecu's.
D2 V8 and Td5 both have electronically controlled trans, no cables.
JC

Yep, change the MAF

Dave